After the unidentified body of a woman is found on some waste ground, the team find themselves becoming involved in the world of vice in a town where nobody is happy to talk. Banks also has to deal with a personal tragedy.
The officers are dismayed to learn the arson attack on the Osgoods' house has injured Michael and killed his son Robbie, and local bully Gary McCready is soon questioned. As the investigation into Katrin's hug continues, the body of an older man who died of natural causes is found buried near her grave, and when Banks suspects Jason McCready abducted missing Annika, he uncovers a shocking secret. Meanwhile, the detective gives a moving speech at his mother's funeral, and the ceremony brings him closer to his father.
A husband and daughter find it hard to deal with their grief after the body of wife and mother Anaan Kamel is discovered washed up by an underground river. Marcus Leyton, a former employee of Anaan and Raheel's law chambers becomes the main suspect.
After the body of a university undergraduate is discovered dumped in a ravine the investigation into hismurder reveals he was not a model student. Helen's professional relationship with Banks comes under threat when somebody from her past shows up she has has found hard to forget.